From b55e9545f2092b27799a45ed4d4690df5bc1296f Mon Sep 17 00:00:00 2001
From: Jingyue Wu <jingyue@google.com>
Date: Fri, 24 Apr 2015 02:57:30 +0000
Subject: [PATCH] [NVPTX] Emits "generic()" depending on the original address
 space

Summary:
Fixes a bug in the NVPTX codegen. The code used to miss necessary "generic()"
on aggregates of addrspacecasts.

Test Plan: addrspacecast-gvar.ll

Reviewers: eliben, jholewinski

Reviewed By: jholewinski

Subscribers: jholewinski, llvm-commits

Differential Revision: http://reviews.llvm.org/D9130

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235689 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/NVPTX/NVPTXAsmPrinter.cpp     | 10 +++++-----
 lib/Target/NVPTX/NVPTXAsmPrinter.h       | 16 +++++++++++++---
 test/CodeGen/NVPTX/addrspacecast-gvar.ll |  2 ++
 3 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/lib/Target/NVPTX/NVPTXAsmPrinter.cpp b/lib/Target/NVPTX/NVPTXAsmPrinter.cpp
index 9a719644c56..12170a680d4 100644
--- a/lib/Target/NVPTX/NVPTXAsmPrinter.cpp
+++ b/lib/Target/NVPTX/NVPTXAsmPrinter.cpp
@@ -1179,7 +1179,7 @@ void NVPTXAsmPrinter::printModuleLevelGV(const GlobalVariable *GVar,
       if ((PTy->getAddressSpace() == llvm::ADDRESS_SPACE_GLOBAL) ||
           (PTy->getAddressSpace() == llvm::ADDRESS_SPACE_CONST)) {
         const Constant *Initializer = GVar->getInitializer();
-        // 'undef' is treated as there is no value spefied.
+        // 'undef' is treated as there is no value specified.
         if (!Initializer->isNullValue() && !isa<UndefValue>(Initializer)) {
           O << " = ";
           printScalarConstant(Initializer, O);
@@ -1788,7 +1788,7 @@ void NVPTXAsmPrinter::bufferLEByte(const Constant *CPV, int Bytes,
         }
         if (Cexpr->getOpcode() == Instruction::PtrToInt) {
           Value *v = Cexpr->getOperand(0)->stripPointerCasts();
-          aggBuffer->addSymbol(v);
+          aggBuffer->addSymbol(v, Cexpr->getOperand(0));
           aggBuffer->addZeros(4);
           break;
         }
@@ -1810,7 +1810,7 @@ void NVPTXAsmPrinter::bufferLEByte(const Constant *CPV, int Bytes,
         }
         if (Cexpr->getOpcode() == Instruction::PtrToInt) {
           Value *v = Cexpr->getOperand(0)->stripPointerCasts();
-          aggBuffer->addSymbol(v);
+          aggBuffer->addSymbol(v, Cexpr->getOperand(0));
           aggBuffer->addZeros(8);
           break;
         }
@@ -1839,10 +1839,10 @@ void NVPTXAsmPrinter::bufferLEByte(const Constant *CPV, int Bytes,
   }
   case Type::PointerTyID: {
     if (const GlobalValue *GVar = dyn_cast<GlobalValue>(CPV)) {
-      aggBuffer->addSymbol(GVar);
+      aggBuffer->addSymbol(GVar, GVar);
     } else if (const ConstantExpr *Cexpr = dyn_cast<ConstantExpr>(CPV)) {
       const Value *v = Cexpr->stripPointerCasts();
-      aggBuffer->addSymbol(v);
+      aggBuffer->addSymbol(v, Cexpr);
     }
     unsigned int s = TD->getTypeAllocSize(CPV->getType());
     aggBuffer->addZeros(s);
diff --git a/lib/Target/NVPTX/NVPTXAsmPrinter.h b/lib/Target/NVPTX/NVPTXAsmPrinter.h
index 9b11e70b2ae..82c5a33834d 100644
--- a/lib/Target/NVPTX/NVPTXAsmPrinter.h
+++ b/lib/Target/NVPTX/NVPTXAsmPrinter.h
@@ -86,6 +86,14 @@ class LLVM_LIBRARY_VISIBILITY NVPTXAsmPrinter : public AsmPrinter {
     std::vector<unsigned char> buffer; // the buffer
     SmallVector<unsigned, 4> symbolPosInBuffer;
     SmallVector<const Value *, 4> Symbols;
+    // SymbolsBeforeStripping[i] is the original form of Symbols[i] before
+    // stripping pointer casts, i.e.,
+    // Symbols[i] == SymbolsBeforeStripping[i]->stripPointerCasts().
+    //
+    // We need to keep these values because AggBuffer::print decides whether to
+    // emit a "generic()" cast for Symbols[i] depending on the address space of
+    // SymbolsBeforeStripping[i].
+    SmallVector<const Value *, 4> SymbolsBeforeStripping;
     unsigned curpos;
     raw_ostream &O;
     NVPTXAsmPrinter &AP;
@@ -119,9 +127,10 @@ class LLVM_LIBRARY_VISIBILITY NVPTXAsmPrinter : public AsmPrinter {
       }
       return curpos;
     }
-    void addSymbol(const Value *GVar) {
+    void addSymbol(const Value *GVar, const Value *GVarBeforeStripping) {
       symbolPosInBuffer.push_back(curpos);
       Symbols.push_back(GVar);
+      SymbolsBeforeStripping.push_back(GVarBeforeStripping);
       numSymbols++;
     }
     void print() {
@@ -145,10 +154,11 @@ class LLVM_LIBRARY_VISIBILITY NVPTXAsmPrinter : public AsmPrinter {
             O << ", ";
           if (pos == nextSymbolPos) {
             const Value *v = Symbols[nSym];
+            const Value *v0 = SymbolsBeforeStripping[nSym];
             if (const GlobalValue *GVar = dyn_cast<GlobalValue>(v)) {
               MCSymbol *Name = AP.getSymbol(GVar);
-              PointerType *PTy = dyn_cast<PointerType>(GVar->getType());
-              bool IsNonGenericPointer = false;
+              PointerType *PTy = dyn_cast<PointerType>(v0->getType());
+              bool IsNonGenericPointer = false; // Is v0 a non-generic pointer?
               if (PTy && PTy->getAddressSpace() != 0) {
                 IsNonGenericPointer = true;
               }
diff --git a/test/CodeGen/NVPTX/addrspacecast-gvar.ll b/test/CodeGen/NVPTX/addrspacecast-gvar.ll
index 6afbdb8a429..b87c05b87ef 100644
--- a/test/CodeGen/NVPTX/addrspacecast-gvar.ll
+++ b/test/CodeGen/NVPTX/addrspacecast-gvar.ll
@@ -3,7 +3,9 @@
 ; CHECK: .visible .global .align 4 .u32 g = 42;
 ; CHECK: .visible .global .align 4 .u32 g2 = generic(g);
 ; CHECK: .visible .global .align 4 .u32 g3 = g;
+; CHECK: .visible .global .align 8 .u32 g4[2] = {0, generic(g)};
 
 @g = addrspace(1) global i32 42
 @g2 = addrspace(1) global i32* addrspacecast (i32 addrspace(1)* @g to i32*)
 @g3 = addrspace(1) global i32 addrspace(1)* @g
+@g4 = constant {i32*, i32*} {i32* null, i32* addrspacecast (i32 addrspace(1)* @g to i32*)}
-- 
2.40.0